How to Install Apache Cassandra on CentOS 7

Cassandra Installation on CentOS 7.x

Before Installing Cassandra, we need to Install Java 8;

yum update -y

wget –no-cookies –no-check-certificate –header “Cookie:oraclelicense=accept-securebackup-cookie” “http://download.oracle.com/otn-pub/java/jdk/8u131-b11/d54c1d3a095b4ff2b6607d096fa80163/jdk-8u131-linux-x64.rpm”

yum -y localinstall jdk-8u131-linux-x64.rpm

We can check java version as down below;

To install Cassandra, we need to add following parameters into /etc/yum.repos.d/cassandra.repo

[cassandra]

name=Apache Cassandra

baseurl=https://www.apache.org/dist/cassandra/redhat/311x/

gpgcheck=1

repo_gpgcheck=1

gpgkey=https://www.apache.org/dist/cassandra/KEYS

You can use “vi” command to enable to insert as down below;

vi /etc/yum.repos.d/cassandra.repo

Now, we can install Cassandra;

yum install cassandra -y

systemctl daemon-reload

systemctl start cassandra

systemctl enable cassandra

You can verify that Cassandra is running by typing the following command;

nodetool status

Cassandra comes with command line shell cqlsh to run query.

To access CQL shell, run the following command.

[root@         ~]# cqlsh

Connected to Test Cluster at 127.0.0.1:9042.

[cqlsh 5.0.1 | Cassandra 3.11.0 | CQL spec 3.4.4 | Native protocol v4]

Use HELP for help.

Cassandra – Create KeySpace (Database)

After run the command “cqlsh”, we are now able to create KeySpace as down below;

CREATE KEYSPACE SQLSarper WITH replication = {‘class’:’SimpleStrategy’, ‘replication_factor’ : 3};

We created a keyspace “SQLSarper”, now we can Access into the keyspace with following command;

Use SQLSarper;

Now we can create our objects.

Let’s create a table on SQLSarper KeySpace;

After Access into SQLSarper KeySpace with “use SQLSarper” command, we can create our table;

CREATE TABLE Staff (

Personel_Id int PRIMARY KEY ,

Personel_Name varchar,

Personel_Surname varchar,

Personel_Email varchar

);

ALTER TABLE

Add Colomn;

ALTER TABLE Staff

ADD Adress text ;

We can check the table with “SELECT * FROM Staff ;”

Drop Colomn;

ALTER TABLE Staff

DROP Adress ;

DROP TABLE

–Create a table

CREATE TABLE Deneme

(

ID INT PRIMARY KEY,

Text text

);

–Insert data into the table

INSERT INTO Deneme (ID,Text) VALUES (1,’SarperERKOL’);

— Check the table

SELECT * FROM Deneme;

–Delete the table

DROP TABLE Deneme;

TRUNCATE TABLE

TRUNCATE TABLE Personel;